You mentioned Rome, and just as a mandatory heads up, while it's not bad, HBO's Rome is rather far from being an accurate portrayal of Rome :) If you'd like to read more about the events of the show (specifically the first season), look no further than Adrian Goldsworthy's excellent biography of Caesar - Caesar: Life of a Colossus. If you'd like a tome that solidly covers all areas of Republican Roman history (Basically ca. 753-44 BCE) in a rather amazing way, check out the sourcebook that's recommended in the booklist. If you're interested in the way the military worked (and why a good bit of the show's portrayal of that military is ridiculous), check out Adrian Goldsworthy's The Complete Roman Army and Stephen Dando-Collins' Legions of Rome: The Complete History of Every Imperial Legion.

Reading Caesar's own work is also fantastic for understanding context, and Caesar's Gallic Wars are extremely well written, entertaining, and informative. Heck, they were literally written as entertainment for the masses of Rome, and people today are the same as they were a couple of millenia ago :)

I think that basically covers it. If you just want one book, however, Life of a Colossus is the way to go. It's my go-to book for the 1st c. BCE, and it describes the surrounding context of the period extremely aptly. Best of luck!

Please see the AskHistorians booklist.

Unfortunately, I am not sure that this question conforms to the rules of the subreddit. Questions should (I believe) be directly about history. From the rules: "Questions should be about an event or person or culture in history."